There have been night-time searches of Palestinian homes in the West Bank. Israeli soldiers have climbed down into wells. They've scoured caves. And beefed up security at checkpoints, in the search for three Israeli teenagers who were kidnapped almost two weeks ago.

Israel is a country on edge, with people glued to their radios and televisions waiting for word about the three young men. Their names — Eyal, Gilad and Naftali — are uttered in cafes, printed on posters calling for their return, and said in prayer at synagogues.

At the same time, Israel has faced criticism from human rights groups, after launching the largest security operation in the West Bank in years, looking for the teens. Four Palestinians — including a teenager — have been killed by Israeli forces. More than 400 people have been arrested.

Naftali Fraenkel and Gilad Shaar, both 16, along with Eyal Yifrach, 19, were abducted on June 12 while hitchhiking near a Jewish settlement in the West Bank, north of Hebron. The boys had just finished classes at a Jewish seminary.

Their mothers travelled to Geneva Tuesday to speak before the United Nations Human Rights Council.

"I have come here before the UN, before the world, to ask everyone to do whatever they can to bring our boys back," said Rachel Fraenkel, who, like her son, holds joint Israeli and U.S. citizenship.

"My son texted me, he said he is on his way home," Fraenkel said. "And then he is gone. Every mother's nightmare is waiting and waiting endlessly for her child to come home."

Israel's prime minister Benjamin Netanyahu says there is "unequivocal" proof that the Islamic militant group Hamas is responsible for the kidnappings, but he has yet to provide any proof to back his assertion.

Israeli soldiers take part in an operation to locate three Israeli teens in valley of Haska near the West Bank City of Hebron on June 24. (Mussa Qawasma/Reuters)

Netanyahu has demanded that the president of the Palestinian Authority, Mahmoud Abbas, disband the unity government he formed with Hamas earlier this month, which replaced separate administrations of rival factions in the Gaza Strip and West Bank.

Abbas has rejected Netanyahu's demand, saying the Israeli prime minister has failed to provide proof of any Hamas involvement.

The Hamas leader, Khaled Mashaal, said his group has no information about the kidnapped Israeli teens, but said those who abducted them are "blessed" if the kidnappers can force the release of Palestinians in Israeli custody.

Abbas has faced intense criticism from many Palestinians since he stated that Palestinian security forces would assist in efforts to find the kidnapped boys.

"We are co-ordinating with them [Israel] to reach them," Abbas said of missing teens. "They are human beings and we care about the lives of human beings."

Abbas called traitor

Early Sunday, Palestinian demonstrators in the West Bank city of Ramallah threw stones, first at Israeli forces in the city carrying out searches. But they soon directed their anger to Palestinian police, stoning a police station after officers retreated inside. (Palestinian security forces, under an agreement on security co-operation, must remain inside their buildings while Israeli forces are carrying out operations.)

"We don't want security co-operation," chanted dozens of Palestinians on Monday, another example of how Abbas's position is putting him at odds with his public. Abbas has been called a traitor and has received death threats on social media.

Some Palestinian leaders have complained that Israel's crackdown inside the West Bank is driving up support for Hamas, after the Palestinian Authority has taken measures to decrease the militant group's influence, at least in the West Bank. The PA has shut down Hamas-linked charities and arrested some its members.

The Israeli response to the kidnappings, called Operation Brother's Keeper, involves thousands of soldiers, police officers and security agents. While they have yet to find the missing teenagers, Israel has used the operation to deal a blow to Hamas and dismantle its infrastructure in the West Bank.

More than 250 Hamas members have been arrested, some of whom were set free from Israel prisons in 2011 in exchange for the Gilad Shilat, the Israeli soldier held for five years in Gaza by militants with ties to Hamas.

Rising death toll

The Israeli operation in the West Bank has drawn criticism of human rights groups, who say it amounts to little more than "collective punishment."

The United Nations undersecretary for political affairs warned Israel against "punishing individuals for offences they have not personally committed."

"The rising death toll as a result of Israeli security operations in the West Bank is alarming," Jeffrey Feltman told the Security Council on Monday.

There were signs Wednesday that the Israelis were winding down their operation, ahead of the start of the Muslim holy month of Ramadan, which begins on the weekend.

While more than 2,000 Palestinian houses have been searched in nearly two weeks, Israeli security officials say they will relax some of the restrictions placed on communities in the West Bank, in part to ease tensions.